3900 TB options

[ericjon262]

is it possible to give a 3900 PCM a TPS signal and ditch the DBW throttle body? I like the idea of VVT, but I hate electronic throttles.

on a side note, please don't post why the DBW TB is good or bad, I've made up my mind on that, and I'd rather move on to if a cable drive TB would work.

[NateD4]

I think if you mapped them in the tune with a linear response curve it might be possible to feed fake TPS signals with a microcontroller set up to mimic the lag times.

There are two ways the DBW system 'could' work. 1) the DBW throttle controller chip feeds data to the ECM that tells it driver intent. 2) the DBW is totally independent of the engine management system. The management system would have to read the sensors to gather state data and run the engine based on it.

#1 will provide some challenges, #2 would make what you are trying to do possible with a bit of microcontroller wizardry.

Does this help at all?

[ericjon262]

I was more thinking along the lines of removing everything DBW from the car, basically reprogramming the PCM to use a propper cable throttle

[NateD4]

Technically speaking almost anything is possible especially with computers. However, the computers in use may not be easy to crack in that regard. I've heard of others asking this question on one of the tuning forums. The problem seems to be in the difficulty of modifying code without re-writing ALL of the software in the computer.

I imagine if you are a talented programer you could insert some custom code into the runtime loop of the ECM, however I'd imagine you'd need to re-map all the variables in the code to work right.

With that said... I'm not quite sure why you want to get rid of DBW... but you may be better off with another computer solution.

But if you are really interested, it may be possible to do. I had hoped to rewrite one myself, but I think it'll be a long term project. The chip used to run the computer isn't super advanced, but its not super simple either.


You may want to figure out what you are looking to spend.

I came across this company: www.dtafast.co.uk

The seem to have a nice reasonably priced customizable setup.

When I talked to them about controlling VGT, VVT and DOD they said they could program it.

I'm not sure if they use custom computers or are reprogramming OEM Ford/GM stuff but they claim a starting price of £450.

Again not sure what your budget or goals are... but getting rid of DBW completely may require an older ECM or custom solution. Personally I like DBW... tuning it may be a different story.

[ericjon262]

this is just thoughts for the future, right now, I'm working with an LX9, which has been adapted to a LX5 TB, I eventually will do a 3900, similar to what joseph upson is doing with his fiero, except, mine will probably be n/a.

[ericjon262]

With that said... I'm not quite sure why you want to get rid of DBW... but you may be better off with another computer solution.

A bad TPS with a conventional throttle makes the car run like shit, a bad TPS with DBW means you don't have control the engine. I've changed way to many TPS's before to think it's safe.